LOCATION BASTON COEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Ustic Natrargids
TYPICAL PEDON: Baston sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
E--0 to 1 inch; light gray (10YR 7/2) sandy loam, grayish brown (10YR 5/2) moist; moderate medium platy structure; slightly hard, very friable, slightly sticky and slightly plastic; violently effervescent, strongly alkaline (pH 9.0); abrupt smooth boundary. (1 to 3 inches thick)
Btn--1 to 12 inches; light brownish gray (10YR 6/2) clay loam, light olive brown (2.5Y 5/4) moist; moderate medium prismatic structure; extremely hard, friable, moderately sticky and moderately plastic; strongly effervescent, very strongly alkaline (pH 9.4); clear wavy boundary. (10 to 15 inches thick)
Bny--12 to 19 inches; light brownish gray (2.5Y 6/2) silty clay, grayish brown (2.5Y 5/2) moist; weak medium platy structure; very hard, friable, moderately sticky and moderately plastic; common fine clusters of gypsum crystals; slightly effervescent, strongly alkaline (pH 9.0); clear smooth boundary. (6 to 10 inches thick)
C--19 to 28 inches; grayish brown (2.5Y 5/2) silty clay, very dark grayish brown (2.5Y 3/2) moist; massive; very hard, friable, moderately sticky and moderately plastic; slightly effervescent, strongly alkaline (pH 9.0); abrupt smooth boundary. (0 to 12 inches thick)
Cr--28 to 38 inches; weathered green sandy shale.
TYPE LOCATION: Moffat County, Colorado; 16 miles south of Powder Wash, Colorado; 2,310 feet north and 330 feet east of the southwest corner of Sec. 21, T. 9 N., R. 98 W. Clay Buttes USGS quadrangle; Longitude: 108 degrees, 25 minutes, 01 seconds west; latitude: 40 degrees, 43 minutes, 26 seconds north.
RANGE IN CHARACTERISTICS:
Soil moisture: aridic regime bordering on ustic.
Depth to paralithic contact is 20 to 40 inches.
Depth to the base of the Btn commonly ranges from 10 to 18 inches.
Mean annual soil temperature ranges from 44 to 49 degrees F.
E horizon
Hue: 2.5Y or 10YR
Value: 4 through 7 dry, 3 through 6 moist
Chroma: 2 through 4
Btn and Bny horizon
Hue: 2.5Y to 7.5YR
Value: 4 through 6 dry, 3 through 5 moist
Chroma: 2 through 4
Texture: clay, silty clay, or silty clay loam
Clay content: 35 to 50 percent
Reaction is strongly alkaline or very strongly alkaline
SAR: of greater than 13
ESP: more than 15 percent
C horizon
Hue: 2.5Y to 7.5YR
Value: 4 through 6 dry, 3 through 6 moist
Chroma: 2 or 3
Texture: sandy clay loam, clay loam, silty clay loam, or silty clay
Reaction: strongly alkaline or very strongly alkaline.
COMPETING SERIES: These are the
Abston,
Giarch, and
Obadia series.
Abston soils have horizons of secondary carbonate accumulation and do not have secondary gypsum accululation. Baston and Abston series were originally separated by moisture regime subclass, but are now both ustic-aridic; the differences in secondary gypsum and carbonates may not adequately separate these soils, hence these series may need to be combined.
Giarch and Obadia soils do not have a paralithic contact.
GEOGRAPHIC SETTING: Baston soils are on hills and plateaus that have a concave surface. Slopes range from 0 to 12 percent. The soils formed in residuum derived from shale, commonly of the Bridger formation. The mean annual air temperature ranges from 42 to 45 degrees F., and the mean annual precipitation is about 7 to 11 inches. Elevation is 6,000 to 7,000 feet. Frost-free period is 75 to 95 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Langspring and Sandwash soils. Langspring soils are deep and have a calcic horizon. Sandwash soils are deep, skeletal, and carbonatic.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; very slow permeability.
USE AND VEGETATION: All areas of Baston soils are non-cultivated. These soils are used principally for livestock grazing. Native vegetation consists of wheatgrass, bottlebrush squirreltail, and budsage.
DISTRIBUTION AND EXTENT: The series is of moderate extent in northwestern Colorado; MLRA 34A. Additional areas may occur in southwestern Wyoming. Approximately 12,500 acres are currently correlated.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Moffat County (Moffat County Area), Colorado; 1991. The series name is coined from the Abston series.
REMARKS:
Diagnostic horizons and features recognized in this pedon:
Natric horizon - from 1 to 12 inches (Btn horizon)
Paralithic contact - at 28 inches (upper boundary of the Cr layer)
Particle-size control section - The zone from 1 to 12 inches (entire argillic horizon)
Series control section - The zone from 0 to 38 inches (all horizons and upper 10 inches of the paralithic material).
Taxonomic version: Classified according to Keys to Soil Taxonomy, Tenth Edition, 2006.
The 01/2007 revision changes the moisture regime subclass to ustic-aridic and the subgroup from Typic Natrargids to Ustic Natrargids.